Descriptions

An attempt has been made to interbreed populations of Acartia clausi from Woods Hole, Massachusetts, and Yaquina Bay, Oregon. Individuals from these populations are morphologically similar, but differ somewhat in size. Cultures from both sources produced many successive generations in the laboratory, but interbreeding with production of viable offspring did not occur. This is evidence that the Atlantic and Pacific populations have diverged in isolation to the level required to be assigned specific rank.